Arctic Weather

The Arctic is a region as enthralling in its beauty as it is inhospitable and unforgiving to those venturing into its chilly embrace. Nevertheless, an indigenous Inuit people have for millennia scratched out a living from this region, but it is only in the last 1,000 years, and then falteringly, that Europeans have paid any regard to it.

Introduction and background

Today it is the focus of hitherto unimaginable interest, if not intrigue. Its natural wealth, once based on furs, fishing, whaling and sealing, now embraces oil and gas, with its attendant economic, environmental and political implications. More pertinent in the current context is, however, the growing interest in its climate. A curiosity about the region is nothing new, but is today heightened by a growing recognition that not only is it subject to the worst excesses of climate change – witnessed by the shrinking ice and retreating glaciers giving rise to irrevocable loss of habitat to a variety of vulnerable species – but that it is itself, in turn, a major driver of the global climatic system ‘feeding back’ (to use the term preferred by scientists) into the climates elsewhere on the planet.

Nowhere is witnessing, or expected to witness in the future, such warming as is taking place here, and nowhere are the consequences more profound. But why should this be the case? The answer, in part at least, lies in the accident of its geography. Whereas the Antarctic region is a vast continental land mass surrounded by water – making it thereby more resistant to the consequences of climate change – the Arctic region is quite the opposite: a large ocean basin surrounded by land. Greenland excepted, much of its icy surface rests, rather sensitively, on the Arctic Sea and is not bedded on the securer foundation of land. As this relatively thin ice cover retreats there are two important consequences. Firstly, it exposes the waters of the Arctic Sea to direct solar radiation and, secondly, the loss of the near-white ice cover changes the so-called ‘albedo’ of the Arctic surface. Albedo is the degree to which the Earth’s surface reflects (rather than absorbs) in-coming short-wave radiation from the Sun.

Over most land and sea surfaces, while the albedo varies notably, it is in the order of some 5%, which is to say that those surfaces absorb around 95% on incoming radiation, converting it to the heat which then either directly or indirectly warms the lower atmosphere. It is indeed, if we ignore the trifling contributions from geo-thermal sources, the only means by which our atmosphere receives the energy needed to drive the climate system and produce our weather.

The Arctic presents a quite different picture to us. The snow and ice cover has a high albedo and reflects away over 90% of incoming solar radiation, which consequently is not available for producing any atmospheric warming. Hence, even during the long, occasionally endless, summer days, little of the sunlight serves the purposes it does elsewhere. As the ice retreats, however, this albedo changes to the much lower levels of open water surfaces.

Arctic waters, previously covered by ice are now free to absorb radiation and warm up, storing the heat energy and rendering it so much more difficult for the sea-ice to re-extend southwards as winter advances and air temperatures fall. It is for these reasons that the Arctic responds more sensitively to climate change while its rapid warming and loss of ice cover in response to changing albedo provides a new and significant element in the global climate system.

Such considerations prompt the curiosity of the scientific community, which now more than ever needs to know as much as possible about the present, and past, climates in order to make thereby more reliable predictions of the future of this most mercurial of climatic zones. Yet, and perversely, it is the climate itself that has hindered this search.

Whereas large parts of Europe and, to a lesser degree, North America enjoys the benefits of a resident population with a natural interest in the world about them going back centuries and, more recently, well-organised national observational networks of weather recorders; the Arctic possesses no such rich legacy of observations and data. This is not, however, to suggest that the region lacks any form of past documentary record: it does, and the – as yet incomplete – endeavours in this field occupy the rest of this item.

For reasons of trade, adventure, political intrigue and, more recently, genuinely scientific interest, the region has attracted a succession of Europeans. There is, however, only one means of arriving in the Arctic from Europe and that is by sea, and this characteristic has imparted a particular flavour to many of the older documentary records; these being mostly the logbooks kept by the generations of intrepid mariners who, for so many reasons, were drawn there.

A more general review of logbooks from around the world’s oceans as a source of information on climate change was offered in a recent edition of this journal (Wheeler, 2014), but here attention is largely concentrated on a small yet important subset of the logbooks of the UK archives from Arctic voyages. The subject serves simultaneously to illustrate how such archive sources can inform climate change studies.

Arctic documents

The documentary record goes back to start of the last millennium and the famous Vinland and Greenland Sagas, which relate the adventures of the out-lawed Icelander, Eirik the Red. In common with so many such sources, this record was not written with any scientific interest in mind and one must divine from its pages the climatic message. This is not the arena in which to explore the richness of the saga records, suffice to state that the collective record, especially of the Greenland colonies, suggests a local climate less severe, more benign and accommodating than even that of today. How far, however, this ‘Medieval Warm Period’ was a local, rather than global, phenomenon is a matter of rich debate. Most evidence suggests the former rather than the latter.

As far as British records are concerned, there is nothing extant until the four voyages of William Baffin between 1612 and 1616; the earlier voyages of Henry Hudson and John Cabot have, sadly, left no corresponding record. Baffin’s logbooks repay attention and have been published in extenso by the Hakluyt Society (Markham, 1881). It was, however, not science that drew these first British explorers; it was trade and the search for the fabled North West Passage to the Orient, and this search was to continue to excite the imagination of explorers for centuries to come, with sometimes tragic consequences.

Baffin’s detailed observations on the conditions he found suggest degrees of ice cover that would today be regarded as exceptional. But his too few voyages provide little more than a snapshot, a mere vignette, of what may have been temporary conditions, although clearly far less accommodating to easy sailing than those encountered half a millennium before by Eirik the Red and his companions.

A useful insight into the climate of past decades and centuries can be provided only by a long series of records that chronicle not only the weather, but allow also the interpretation of its longer-term counterpart: the climate. Such records had to await the emergence of more organised and regular ventures to the Arctic. In terms of UK sources two such enterprises stand out; those of the Hudson’s Bay Company, and of the British whaling fleet.

To these might be added the more detailed but also more sporadic records of the Royal Navy’s so-called voyages of exploration; mostly in search of the North West Passage but also, and at the behest of the Royal Society, taking groups of scientists with a brief to measure and describe the Arctic environment and conditions they encountered.

Hudson’s Bay Company’s legacy

First in this particular field was the Hudson’s Bay Company (HBC). The Company was awarded its Royal Charter in 1670 with a responsibility to trade, principally in furs, from the vast area that is now northern Canada. The climatologically-useful records of this admirable enterprise, however, begin only in 1750, but persist through to the 1880s. These records consist of the logbooks kept by the captains of the Company’s vessels that sailed annually between the Port of London and the factories in Hudson’s Bay.

These voyages were timed to provide as long as possible in Canada to gather and load the furs, but to leave before the winter ice closed in. For this reason the outward voyages tended to leave London in late March or April, with the return being made in September. Consequently, while an ‘annual’ century-long record of the voyages has come down to us, the year is seen only refracted only through the prism for those months; the records while in port tended to lack the climatological detail required for present-day purposes, and it was only while at sea that what might be considered a full record was maintained. Nevertheless, at a time when there were almost no other records from these regions even such partial forms of evidence are to be treasured.

The character of these logbooks has been explored in Ward and Wheeler (2012), but it is worth noting that while they contain no instrumental data of the form with which we might be familiar today, they are rich in records of wind force, wind direction and any sea ice or icebergs (‘islands of ice’ as they were then known) as well as notes on the general state of the weather such a fog, snow or rain. Such records are surprisingly useful. Climate change is not merely about temperature changes and equally important, though rarely acknowledged, at least in the wider media, is what might best be called ‘the organisation of the atmosphere’, which is to say the state of the weather, the wind fields (directions and strengths), and these latter can be reliably reconstructed from the logbook records.

Figure 2 is but one illustration of the use to which such derived data can be put. It illustrates nicely the value of a long series of records made under the same conventions and in broadly the same area (in this case the far North Atlantic) and is based on the HBC data from between 1750 and 1850; long before instrumental data were correspondingly available.

It is difficult to over-estimate the value of such seemingly simple graphs and it is worth recalling that there are no other means than logbooks by which such a detailed, literally day-by-day, insight into the weather and climate of those remote places and such distant times can be garnered. As with all such re-creations however, its illuminating conclusions prompt more questions than they answer. Why, for example, does the snowfall record reveal such a marked, and hitherto unknown, increase in the early nineteenth century? And what causes the minimum around 1770? Such thought-provoking graphs have also been produced for fog, rain, wind direction and gale frequency, representing a comprehensive and unique view of the region’s climate. These HBC logbooks are a veritable, as can now be appreciated, cornucopia of scientific information.

The captains of the Company often had a notable curiosity about their surroundings, some writing at length on the conditions in Hudson’s Bay during there summer stays; however, the formal logbooks were principally navigational documents. Close attention to the wind and weather was made, not for scientific purposes, but for the more pragmatic purpose of finding their way safely across the seas and oceans.

Whalers and weather

The same very practical drive is true also of the second major category of documentary evidence for the Arctic, which comes from the logbooks of the British whaling fleet. While superficially similar to those of the HBC documents, they differ in a number of respects. Most importantly there are far fewer whaling logbooks and of the many thousands of such voyages we have only a few hundred British logbooks come down to us (Brown et al , 2008).

These very particular items are scattered around UK Archives, the largest set being found in the Hull History Centre (www.hullhistorycentre.org.uk). Moreover, those that remain do not provide the continuous series offered by the HBC logbooks; there is a mere handful from before 1800 and several gaps in the series from then until the mid-nineteenth century, when large scale Arctic whaling ceased in the UK.

The advantage offered by these logbooks is, however, that the whalers penetrated far further north than did the captains of the HBC ships, their favoured ‘fishing’ grounds being the Davis Straits to the west of Greenland, and the Fram Sea to its east. The preferred catch was the Bowhead Whale ( Balaena mysticetus ), and a peculiar advantage, at least as far as the scientific use of the logbooks is concerned, of this creature is that it feeds on the plankton of the ice margins, and that is where the whalers headed.

As a result the whaling ships dutifully followed the summer retreat of the ice northwards, and its return as winter advanced, though few whalers, at least by design, wintered in these latitudes. Icebergs, which are rather different in some respects to the seasonally fluctuating cover of sea-ice, were also dutifully recorded by vessels hunting in the Davis Straits (where icebergs are abundant, calving off the West Greenland glaciers) and a time series of berg activity has also been constructed identifying periods of intense, and of less intense activity. As a result, and in addition to all the ‘standard’ wind and weather information stored in the HBC logbooks, there is here a reasonable record of summer Arctic ice retreat and iceberg activity, of a form not to recur until the age of satellite meteorology.

The ARCdoc project and the future

Compared with the many thousands of Royal Navy logbooks, the number of Arctic items is very small. That said, they offer, as noted earlier in this article, a unique insight into the past climate of a singularly important region. A recently completed project has brought together the data from all known UK logbooks in the form of the ARCDOC project and an overview of the project can be found at https://arcdoc.wordpress.com.

This undertaking was funded by the Leverhulme Trust and was designed to examine all UK whaling and HBC logbooks for the period 1750 to 1850. Its principal objective was to prepare the data in a form that could be made easily accessible by the wider scientific community and to develop a set of methods for handling such information as it is rarely in a form that allows for immediate scientific interpretation. The project is now complete and the extracted data are held in a publicly-available database (www.hull.ac.uk/mhsc/ARCDOC/).

The results reveal, and figure x offers a good example, of a degree of climate variation previously suspected but not hitherto supported by objective evidence. There is also evidence, if not of persistent, certainly of occasional seasons of notable severity, that of 1830 being the most, and tragically, spectacular – arguably a summer that sounded an early death knell for British Arctic whaling.

Valuable though these data sets and preliminary findings are, much remains to be accomplished in the field of data recovery and this is by no means the end of the story. ARCdoc confined its attention to UK HBC and whaling logbooks, but the National Archives in Kew (www.nationalarchives.gov.uk) hold many logbooks of the Royal Navy’s sorties into the region.

These represent a variety of enterprises from simple needs of fishery protection to highly publicised searches for the North West Passage or, tragically in the case of Sir John Franklin’s ill-fated expedition, the search for lost crews and explorers. These logbooks, while containing the standard observations required by the Admiralty on wind and weather, were often supplemented by detailed, sometimes hourly, weather observations using instruments such as thermometers and barometers that were not part of the usual equipment carried on board.

Their presence was the result of the close associations that existed in the nineteenth century between the Royal Society and the Royal Navy, the latter agreeing to carry small groups of scientists on their voyages of discovery. Their records are as fascinating as they are occasionally bizarre, witnessed by the following taken from an account by George MacDougall (1857) while on board HMS Resolute, sent in search of the lost crew from the Sir John Franklin expedition:

Sun. 23rd, at 1am. The quartermaster went outside on the floe, to register the thermometers, which were kept in a box secured to a table. In the act of reading off, his attention was attracted by a slight noise, and his surprise may be imagined, when, on looking around, he observed a bear within five yards of him. His situation, to say the least of it, was not an enviable one, for one spring of the brute would put an end to him registering thermometers forever.

Moreover, Arctic logbooks are found in other countries too, not least the United States, whose New England coast had a long tradition of whaling, and other European nations such as Denmark and Norway. In all these cases the archives have barely been explored to see what further sources of valuable information might be found there. It is very much a matter of ‘watch this space’.

Meanwhile the Arctic is subject to closer and more scientifically-directed scrutiny than has ever been the case in the past. Satellite observation systems have of course revolutionised the whole process of data acquisition and enable a geographic spread that embraces the whole of the Arctic almost ‘at a glance’; a matter of particular importance when plotting the annual rhythm of sea ice advance and retreat.

Nevertheless a place remains, as it always has, for meticulous direct measurements of meteorological variables such as temperature and air pressure and such networks are now very much a part of routine practice across the region. But such enterprises in order to provide maximum benefit from the various enterprises, require cooperation on an international scale. In this respect the work of bodies such as the International Arctic Science Committee (http://iasc.info ) are of global significance.

Founded in 1990, and constituted on 23 countries, the IASC’s remit now embraces, importantly, not only the physical environment of the Arctic but also works with the indigenous communities whose wellbeing is of fundamental and now recognised importance and no less under threat. This is an arena in which the physical and social sciences work productively, and positively, together. We have indeed come a long way since the age of whaling with harpoons from flimsy wooden boats.

Published: 11th May 2016 in AWE International